The problem, as Media Matters points out, is that the wording of the Rasmussen poll ("Did Bush know about the 9/11 attacks in advance?") almost surely conflates people who believe Bush intentionally allowed an attack to occur with those who think the administration was negligent in its attention to the potential threat from Al Qaeda. Even National Review Online's Jonah Goldberg conceded this point in a column published soon after the poll was released.

There are also accusations being made following the 9/11 terrorist attack. One of these is: People in the federal government either assisted in the 9/11 attacks or took no action to stop the attacks because they wanted to United States to go to war in the Middle East.

When asked how likely this was, 16% of Americans said it was very likely and 20% said it was somewhat likely that people in the Bush administration "assisted in the 9/11 attacks or took no action to stop the attacks because they wanted to United States to go to war in the Middle East."

The partisan breakdown was not provided in the Scripps news report on the poll, but using the weighted data provided by Scripps (see update below), we can directly compare the proportion of incorrect or don't know responses to the 9/11 conspiracy and Obama birth certificate questions:

There is an undeniable symmetry to the misperceptions, which skew in the expected partisan directions in both cases. The total proportion of incorrect or don't know responses among Republicans on Obama's citizenship (58%) is comparable to the proportion of comparable responses among Democrats on a 9/11 conspiracy (51%).

The pattern of responses by party is similar if we only include those respondents who directly endorsed the misperception in question (i.e. "very likely" to be a 9/11 conspiracy, Obama not a citizen):

Even under this more stringent standard, 23% of Democrats and 28% of Republicans indicated direct support for the misperception of interest.

In short, using a more appropriate comparison poll, the primary conclusion stands -- both party's bases are disturbingly receptive to wild conspiracy theories.

Update 8/10 1:39 PM: I've updated the response totals and graphics based on data provided to me by Scripps that is weighted by race, age, and gender to match Census figures. Applying these survey weights results in slightly higher estimated levels of misperceptions on the 9/11 conspiracy question than I previously reported. This accounts for the discrepancy between the publicly available Scripps data and their published results that I mentioned in the initial version of this post.

Update 8/15 10:39 PM: I just discovered that the first chart had not been updated to reflect the correct weighted response totals. Apologies -- it has been corrected above.

Comments

Well done, Brendan.

I'm guessing that three principles are at work here. One, mentioned several times by Rob, is that any nutty theory seems to have some support.

Second is a variant of Brendan's 8/6 point that when the media give airtime and column inches to misinformation, they make it plausible. In this case, I think including the silly theory as an option on a poll gives it a certain plausibility to those being polled.

A third principle is that partisans tend to give credence to information that supports their beliefs and to disbelieve information that contradicts their beliefs. As I recall, this principle is discussed in the book, How We Know What Isn't So: The Fallibility of Human Reason in Everyday Life by Thomas Gilovich

both party's bases are disturbingly receptive to wild conspiracy theories.

You seem to be ignoring the Independent category in your analysis. The "Birther" conspiracy appears to be almost exclusively Republican (28% of Republicans strongly believe it compared to 8% of Independents), while the "9/11" conspiracy is less widespread and less polarized (23% of Democrats versus 16% of Independents).

These questions also seem to conflate people who actively believe a conspiracy theory with those who could believe it but hadn't heard about the conspiracy before being asked by the pollster.

I suppose this would fall under push-polling. Has anyone done a study to see how likely partisans are to believe a conspiracy they couldn't possibly have heard before (e.g. one created by the pollster, himself)?

I still think that wording is wildly unfair. After all, we do know that the President was warned that Bin Laden was "Determined to Strike in US" and that instead of listening to Clarke's hair-on-fire urgings to do something about it, Cheney was deciding which companies would get Iraqi oil revenue. We can argue about intentionality, but it seems clear that a) they were told Bin Laden was going to attack, b) they didn't do anything about it, c) they did make plans to invade Iraq.

Polls that actually test for conspiracy theories (were there bombs in the towers? was WTC7 hit by a missile? was the US behind the attacks?) find support closer to 6% nationally.

Statistics for conspiracy theories are meaningless. The conspiracy, if either happened, by definition would not be widely known or believed. You can't claim someone is crazy for thinking something different than you. Especially when, for example, you have hundreds of high profile individuals who have also stepped out with *evidence* beyond just their belief (like the truther's patriotsquestion911.com site).
I would hesitate to ever say birthers are crazy. Sure, crazy people do get attracted to such theories, but they do not maintain and organize them -- as truely insane people tend not to be terribly good at organizing. As far as theories go, there's is definitely on shakey ground because they are based on a supposed lack of evidence, rather than a mounding pile of actual evidence.

The equivalence between the two conspiracy theories is misguided. Believing Obama was born abroad assumes that a white American woman from Kansas with nine months to plan her delivery would prefer Kenyan medical facilities to American hospitals in 1961 (and that she would doctor a birth certificate to hide her penchant for venturous medical tourism). Truthism stems from the belief that Bush was militantly hawkish (he was) and reckless with American lives (he was) and that his administration was obsessively secretive (it was). Granted, the MAGNITUDE of unchecked malice that truthers allege is categorically implausible, but the point is that birthers allege not only malice but a degree of reckless stupidity that's downright absurd.

I think you are spinning, Nabeel. You could just as easily say that Truthism relies on an incredibly complicated conspiracy involving at least dozens of people, with unclear motives, surely horrified by the consequences of their actions and likely to leave a long trail of evidence (why didn't the Al-Qaeda members of the conspiracy come forward once Bush betrayed them and starting hunting them?). Not to mention some really bizarre choices (hijacking a plane, shooting a missile at the Pentagon, killing all the people on the plane, blowing up the plane in a secret location, and then transporting the dead bodies and plane debris to the missile impact site). By contrast, Birthism relies on just one hick family making a stupid decision (let's fly to Kenya!) and then taking some fairly simple steps to cover it up (a few bribes, a few newspaper announcements) for a clear goal (the benefits of American citizenship).

I'm not saying I take this view. I think they're both dumb. I'm just saying any argument about which conspiracy is more plausible is going to be highly indicitive of your sympathies.

Campico, it seems to me you are the one who is doing the spinning. First, you respond to all the 911 theories as if they are one. I haven't heard any theory that bodies were transported to the Pentagon for instance. Furthermore, there doesn't have to be any double crossed Al Qaeda if the Neo cons just allowed an already planned strike to succeed. On the other hand, Obama has a perfectly valid birth certificate. If his citizenship is suspect then so is everyone Else's. That is a fact. At least some 911 theories are based on some real problems with the official story. The birther theories are made up from whole cloth no facts or official story contradictions are given or required. You could say that Obama's birth certificate is a fake but I could say the same thing about your birth certificate. On the other hand, WTC 7 is still the only steel structure building to collapse due to fire alone. That is a fact. There were only 8 pairs of fighters protecting the entire US on that day, the lowest number in the preceding 40 years, that is also a fact. Quite a coincidence in fact. There is no equivalence between these two theories other than you disagree with both of them.

Campico, it sounds like you're talking about more extreme versions of the Truther myth. In that case, yes, that's true. But to me it looks like survey asked whether warning signs were intentionally ignored rather than overlooked. Troubling? Yes. Silly? Yes. I just don't think it's as silly as the Birther myth. Especially since, for the record, his hick mother was all he needed to get his US citizenship--he could have been born in Mars for all our country cares.

A much wider range of the public seems to believe in or be unsure about a 9/11 conspiracy than believe in or are unsure about Obama's birth. Check out the disparity in the Independents column. 20% more are Truthers/uncertain than are Birthers/uncertain.

Also, with about a 14 point spread, Republicans are much more likely to be Truthers/unsure than Democrats are likely to be Birthers/unsure.